Chlorosulfonation of ethylene polymers



Um'e St t s M11 2,972,604 CHLOROSULFONATION 0F ETHYLENE POLYMERS William B. Reynolds and Peter J. Canterino, Bartlesville,

:Okla., assignors to Phillips Petroleum Company, a cor- ,poration of Delaware No Drawing. Filed Sept. 10, 1956, Ser. No. 608,687

6 Claims. (Cl. 260-793) This invention relates to a method of chlorosulfonating ethylene polymers and to the product of such chlorosuland hydroperoxides are useful.

' alpha'-azodiisobutyrate,

mers employed as the starting materials in the present invention. When the prior art method of chlorosulfonating ethylene polymers is applied to the highly crystalline polyethylenes, the products obtained are stifl, nonhomogeneous plastics. However when employing the method of the present invention, chlorosulfonated products containing chlorine even in the same range as the prior art method are produced which are strong flexible plastics as contrasted to rubbery products of the prior art. These plastics are useful both in the unvulcanized condition or they can be vulcanized and when so vul-v 1 canizedthey have physical properties superior tothose of the priorart. In general, the prior art materials hadto be vulcanized to develop suitable physical properties. These prior art ethylene polymers when chlorosulfonated are valuable in the manufacture of gaskets, colored rubbery compositions, protective coatings, monofilaments, films, rubber articles, plastic pipes, etc., however, the flexural strength is not as high as is desirable. The polyethylenes of high crystallinity and high density cannot be satisfactorily chlorosulfonated by prior art methods since the products so produced are high melting, nonhomogeneous materials even in'the region employed by the prior art forproduction of rubber-like products.

An object of this invention is to provide a method for chlorosulfonating ethylene polymers of high crystallinity and high density.

Another object of this invention is to provide a novel chlorosulfonated ethylene polymer.

Still other objects, advantages and features of this invention will be apparent to those skilled in the art having been given this disclosure.

- -According to this invention, an ethylene polymer having acrystallinity of at least 70 percent at room temperature as determined by nuclear magnetic resonance and a densityof at least 0.94 is dissolved in solvent at high temperature and thematerial contacted with suflicient chlorine to solubilize the polymer even at atmospheric pressures and ambient temperatures after which the chlorosulfonation is completed. The chlorination can be carried out in a high boiling solvent or pressures can be used in conjunction with the usual chlorinating solvents.

The sulfonating agentcan be added along with the initial chlorine or can be added after the polymer has been solubilized. The entire reaction can be carried out at the high temperatures, or the materials can be first solubilized, cooled and then chlorosulfonated. The initial or solubilizing step is generally carried out at a temperar 2,972,604 Patented 7 F b- 1961 and lower can be used so long as the polymer is solubilized.

The chlorosulfonation is generally carried out under catalytic conditions. Sunlight and artificial light, especially ultraviolet light, have been found effective in promoting the reaction. Also, catalysts such as peroxides Examples of suitable catalyst include 'benzoyl peroxide, diisopropylbenzene hydroperoxides, and cumene hydroperoxides. Azo compounds are also useful as catalysts. Examples of this class of catalysts include dimethyl and diethyl alpha, alpha, alpha-azo-diisobutyro nitrile, and alpha, alpha'-azobis(alpha, gamma-dimethylvaleronitrile).

Properties of the chlorosulfonated polymers of this invention can be varied considerably depending upon the nature of the polymers used as starting materials, upon the chlorine content, and upon the sulfur content. The products in which there is the greatest commercial interest at present are those prepared from high molecular weight ethylene polymers in which the chlorine content is in the range of 10 and 40 Weight percent and the sulfur content is in the range of 0.4 and 3 weight percent. Products prepared by the method of this invention from a given ethylene polymer and having a' chlorine'content in the lower portion of the range will generally be tough, flexible and leathery while those having a higher chlorine content, e.g., between 20 and 40 weight percent will be tough, flexible and elastic. It It will be understood by those skilled in the art that the rubbery products of the prior art cannot be oriented as can flexible plastics. The tensile strength of the products is high and materials having exceptionally high'tensile strength can be obtained by drawing at room or higher temperatures to produce-orientation. Orientation in the polymer can be produced either before or after compounding and vulcanization. Cold drawn raw gum stocks having a tensile strength around 17,000 p.s.i.

can be readily obtained froma high molecular weight chlorosulfonated ethylene polymer having a chlorine content of 17 weight percent and a sulfur content of 1.27 weight percent. In addition to the other good properties mentioned, the products of this invention are resistant to attack by ozone.

The chlorinating and sulfonating agents can be any known to the art, however, chlorine and sulfur dioxide are most generally employed. The chlorine is employed in molecular excess to that of the sulfur dioxide and as has been mentioned sutlicient chlorine is used to obtam 10m 40 weight percent chlorine and suflicient sulfur dioxide employed to obtain a sulfur content of between 0.4 and 3 weight percent.

Carbon tetrachloride, being fully halogenated, is the preferred solvent for use in this invention.

be chlorinated under the conditions employed. Other solvents which can be employed without consuming chlo-' line include chloroform, trichloroethane, and methylene chloride. The art is aware of suitable chlorination solvents and any such solvents can be employed in this invention. However, low boiling solvents such as those mentioned are preferred since, they can be readily separated from the product. However, high boiling solvefits can be employed such as tetrachloroethane andhexachloroethane. Frequently the solubilizing step. willbecarried out with one of these high boiling materials, the solubilized polymer recovered and the chlorosulfonation step carried out in a low boiling solvent. This is desirable since the lower chlorine-content material is more easily separated from these high boiling solvents and lesser amounts of chlorinated by-product from the self However, other solvents can be employed which may or may not,

sesame 3 vent are obtained than if the reaction were carried out in its entirety in the high boiling solvent.

The polymers to which the present invention is applicable are polymers of ethylene having a crystallinity of at least 70 percent at room temperature and preferably at least 80 percent as determined by nuclear magnetic resonance and having a density of at least 0.94 and preferably at least 0.9.6. Density as used in this specification is given in grams per cc. Ethylene polymers which are applicable are homopolymers of ethylene and copolymers of ethylene with minor amounts of other 1olefins of up to 8 carbon atoms per mlecule, and also with conjugated dienes of up to 8 carbon atoms per molecule. Examples of suitable comonomers include propylene, l-bntene, 1- pentene, l-hexene, l-octane, 4-methyl-l-pentene, 4- methyl-l-hexene, 3-ethyl-l-hexene, 6-methyl-1-heptene, S-methyl-l-heptene, butadiene, isoprene, chloroprene, piperylene, 2,3-dimethyl-l,3-butadiene, 1,3-pentadiene, and the like. These homopolymers and copolymers of ethylene are referred to herein as ethylene polymers and it is tobe understood that the term includes copolymers as well as homopolymers. These polymers have recently come into prominence and can be prepared by the method of Hogan et a1. as disclosed in application having Serial No. 476,306, filed December 20, 1954, or by organo-metal catalysts, one particular type of which is disclosed in Belgian Patent 533,362, issued to Karl Ziegler, November 1-6, 1954.

The methodof Hogan-ct al. isparticularly applicable to l-olefins havinga maximum of 8 carbon atoms per molecule and no branching nearer the double bond than the four position, however, other olefin monomers can be polymerized by the process. According to that process, the olefin is polymerized at a temperature in the range of 100 to- 500" in thepresence of- 0.1 to at least 10 weight; percent chromium as chromium oxide, including a substantial proportion of hexavalent chromium, associ ated with atleast one porous oxide selected from the group consisting of silica, alumina, zirconia, and thoria. A preferred catalyst is one comprising 0.1 to 10 weight percent chromiumas the oxide on a silicaalumina support'such as 90 percent silica-1O percent alumina. This catalyst is ordinarily a highly oxidized catalyst which has been activated by high-temperature treatment under nonreducing conditions and preferably with an oxidizing gas. The polymerization is preferably carried out in the liqud phase such as in solution in a hydrocarbon solvent, especiallya paraffin or naphthene which is liquid under the polymerization conditions of pressure and temperature. The product of polymerizingethylene alone or with minor amounts of such copolymerizable monomers as described when prepared by this described method will have the desired crystallinity and density forthepresent invention.

Similarly, polymers of ethylene of the required properties can be produced with certain organo-metal catalysts, one particular system being disclosed'in the aforementioned Belgian patent. polymerization of olefins in the presence of triet-hylaluminum plus titanium tetrachloride, mixtures of ethylaluminum halide with titanium tetrochloride, and the like. However, it should be understood that the starting polymer can be obtained by any source so long as it meets with the requirement of density and crystallinity.

Two methods suitable for the practice of the invention will now be described,

One method for chlorosulfonation ofthe ethylenepolymer comprises dissolving the ethylene polymer in carbon tetrachloride under pressure at a temperature above.

110 C. but usually not exceeding 130 C. Sufiicient. pressure is applied to maintain the solvent in liquid phase at the temperature employed. Chlorine is then introduced, while the mixture is agitated, until a product is. obtained which is soluble in the solvent at atmospheric.

pressure, Generally at least weight percent chlorine is required to produce a material which is soluble in This latter patentdiscloses the carbon tetrachloride at 50 to 60 C. The temperature is then lowered to the 50-60 C. range, the pressure released, and sulfur dioxide and chlorine are introduced, generally simultaneously to give a product containing between 10 and 40 weight percent chlorine. and 0.4 to 3 weight percent sulfur. While it is preferred to carry out the first step of the process at superatmospheric pressure and the second step at atmospheric pressure, the entire reaction can be carried out above C. under pressure if desired. Temperature for the second step, when operating at atmospheric pressure, is generally in the range between 25 and 60 C, It is also possible when the entire reaction is to be carried out at the higher temperature and pressure to simultaneously introduce the sulfur di-. oxide and chlorine as a single step operation. Sulfonyl' chloride can also be used as the chlorosulfonating agent. However, when high chlorine content is desired, additional chlorine can be employed. When using the two step-process of this invention, chlorine can be conveniently used in the first step and sulfonyl chloride in the second step.

As a second method for the chlorosulfonation of the highly crystalline, high density ethylene polymer comprises dissolving the polymer in a high boiling solvent such as tetrachloroethane or hexachloroethane at a temperature between the range of 110 to C., agitating the mixture, and introducing chlorine until a product containing 15 weight percent chlorine is obtained. This step of the process is usually operated in a solution which. contains the ethylene polymer in a concentration between 10 and 50 weight percent. It is an object of this step of the process to provide a product which is soluble in sol; vents such as carbon tetrachloride, chloroform, dichloroethane, trichloroethane, ethylidene chloride, and the like. The reaction mixture from the first step of this process is recovered from the high boiling solvent by pouring the reaction mixture into boiling water or into an alcohol such as methanol, ethanol or isopropanol. The product is dried and then dissolved in a low boiling solvent such as carbon tetrachloride at 25 to 60 C. as about 3 to 5 weight percent solution. Chlorine and sulfur dioxide are introduced, generally simultaneously, to give a product containing between 10 and 40 Weight percent chlorine and 0.4 to 3 weight percent sulfur. The entire process can be carried out in the high boiling solvent, however, this method is not preferred since separation of the product from the high boiling solvent is more difficult than it is from thelow boiling solvents.

EXAMPLE I and a melting point of 245i3 F. Two hundred grams of this polymer was dissolved in 3500 cc. of tetrachloroethane at 110 to 115 C. and grams of chlorine was added while the mixture was irradiated with ultra-violet light. The mixture was coo-led to 90 to 100 C. and an additional 150 grams of chlorine was introduced simultaneously with 30 grams of sulfur dioxide. Irradiation with ultraviolet light was continued throughout the reaction. At: the end of the reaction period, 200 cc. of-

water was added andthe produced coagulated by pouringthereactor contents into isopropyl, alcohol. The result-. ing product was filtered and the coagulated polymerwaswashed w-ith. isopropyl alcohol and dried overnight in a;

vacuum oven at 50 C. and further at 70 C. for 4 hours. Analysis for chlorine and sulfur gave the following re,-

sults; chlorine, weight percent, 295; sulfur, weight pe r.

cent 1.85.

Two hundred grams of polyethylene prepared by con- "52min. Q

ventional high pressuremethodsand'havinga molecular weight of approximately 20,000 was dissolved in carbon tetrachloride and themixturewas irradiated with ultra? violet light while 75 grams of chlorine was introduced. Irradiation was'continued while 20 grams ofsulfur dioxide was introduced simultaneously-with 100 grams of chlorine. At the end of the reaction period, 200 grams of water was added and the mixture stirred for two hours after which it was poured into isopropyl alcohol to coagulate the product The product was separated and washed with isopropyl alcohol and dried in a vacuum ovenovernight at"50' C. Analysis for chlorine and sulfur gave the following results: chlorine, weight percent, 28; sulfur, Weight percent, 1.9.

A"'sa'mple' of commercially chlorosulfonatedf poly-" ethylene was obtained. This commercial sample was a chlorosulfonated product of a polyethylene-prepared by the prior art high temperature method. The commercial sample contained 27.5 weight percent chlorine and 1.5 weight percent sulfur. This material in uncompounded condition had a tensile of 125 psi. and an elongation at break of 2100 percent.

Each of the above three products were compounded according to the following recipe:

Parts by Weight 01 cr Ro inY ood Precipitated calcium blac oxide Each ofthe compounded stocks was cured 30 minutes at 320 F. and certain physicalv properties were determined. The following results were obtained:

108 grams of chlorine and; grams of sulfur dioxide were added simultaneously while the mixture was irradiated with ultraviolet light. The addition of chlorine and sulfur dioxide required approximately one hour. 5 At the end of this period 500 cc. of water was added, the mixture cooled with an ice bath, and then poured into isopropyl alcohol. The product coagulated and was washed with' additional isopropyl alcohol after which it .was dried. Analysis showed the chlorine content to be 1017.0 weight percent and .the. sulfur content to be 1.27

4 weight percent.

V Two portions of the chlorosulfonated ethylene polymer were compounded in accordance with the following ""recipes:

Parts by Weight vChlorosulfonated polymer. 40 60 Hydrogenated Rosin l 1.5 Calcium Carbonate 32 Magnesium oxide- 8 12 Dipentamethylenethiuram tetrasulflde 0. 4 0. 6

v The compounded stocks were cured at 300 F. for

minutes: "Elongationand tensile strengths were determined'for each stock. Measurements'were made onan Instron tester using a crosshead speed of, 20 inches per minute. Each of the values given below represents an 30 average, of two tests. Q

Elongation, percent -4.-. .Te s l m EXAMPLE III Y Ethylene was prepared in a similar manner as in the RECIPE A F. 200 F. Shore Hardness Maxi- Resi- Swell 1 Ozone Chlorosulfonated Material Compresmum hence, Percent Resistsion set Tensile, Elonga- Tensile, Percent Orrgi- 14 days ance p.s.i. tion, p.s.i. 119.1 7 days at 70 0. Rating 1 Percent I v v Invention Product 13. 7 3, 170 200 1, 680 65. 0 87. 5 89. 5 19. 2 Conventional Product. 24. 5 3, 180 200 1, 490 83. 5 86 21. 8 0 Commercial Product 28. 5 2, 680 200 1, 200 63. 9 79. 5 82 2 .26. 6

RECIPE B Invention Product 12.4 4, 110 175 I 1, 500 44. 7 91 91 20. 3 0 Conventional Product 19. 5 2,000 150 1, 150 88 87 v 28. 1 0 Commercial Product 19. 4 3, 320 200 l, 250 66.0 81. 5 86. 5 34. 9 0

1 Swelling test made in SAE 10 heavy duty motor oil. 1 A rating of 0 indicates no cracking.

Fromtheabove data, it can be seen that the product Additional runs'were made to determine the effect of orientation on tensile strength and to determine properties. in a different compounded stock." Ethylene was polymerized in a manner similar to that described in Example I to a polymer having a molecular weight or 48,100 (determined by viscosity), a density or 1 0.960, a melting point of 236:2 F. and a crystallinity gof ever 90 percent.

, Due hundred thirteen grams of the polymer was dissolved in 3 liters of tetrachloroethane at C. and

the'..'

preceeding examplesaccording to the method of iI-I( gz:1i1 etal. and the product had the following properties:

Ash, Wt. percent 0.52 Volatiles, wt. percent 0.48 60 Molecular weight 48,100 Density, gm./cc 0.960 Melting point, F 246:2

. 'One hundred grams of thepolymer was dissolved in two litersof'tetrachloroethane at C. and grams 65 of chlorine plus 20 grams of sulfur dioxide were added simultaneously while the mixture was irradiated with ultravioletlight. The addition of chlorine and sulfur dioxide required approximately two hours. The temperature was maintained at 115l20 .C: during this 70 period. The mixture was then cooled to. 80 C. and poured into isopropyl alcohol thereby coagulating the polymer. The product was washed-"with additional al- "coholand dried. The chlorosulfonated material had a chlorine content of 16.4 weight percent and a sulfur 75 content of 0.69 weight percent. 1

rwr-gzerv i..a

I Aportion of the rawpolymer was compression molded 8 The data on the physical properties are tabulated below.

at 300 F. for 5 minutes. This product had a tensile Com- Tensile I Ghlorosullonated Minutes pression 300% Elonga- Resll- Shore :Swell. .Ozone Polymer Cure at Set, Modulus, tlon, lence, Hardness percent Resis- 320 F. percent p.s.i. 80 F., 209 F., percent percent tance 2 .p.s.i. .p.s.i. i

I 20 3 a 180 1 620 68' s1 33 4 o 20 i3.

Invent 34 3,150 7 220 75 a, 250 265, r V 2 a 1 390 62 s 79 26 a 0 -30 8.5 I p "f1?"r?'tt 4 2,870 p155. p

l 14 days at 158 F in SAE oil. 9 0 equals no cracking.

strength of 2102 psi and an elongation of 738 percent. This molded product was cold drawn at the rate of two ovenagedmhw at 212 inches per minute to produce orientation. Tensile 2o chloroslulfona'ted T .1 R strength of the oriented material was 17,800 p.s i. (tensile v i jif gfigg? 33,533? specimen pulled at the rate of 12 inches per minute). 320 F.

A second portion of the chlorosulfonated polymer was compounded using the following recipe;

parts by weight In t on.

Chlorosulfonated polymer -60 Hydrogenated rosin 1.5 loommemia; Magnesium oxide I p .12 Dipentamethylenethiuram tetrasulfide 0.6 5

From the above data, it canbeseen that the blended EXAMPLE IV A run was made to show the operability of the method on an ethylene copolymer and the physical properties compared with the commercial chlorosulfonated ethylene polymer of Example I, Thecopolymer used was a 5050 blend of a 85/15 ethylene-propylene copolymer and a 93.5/6.5 ethylene-propylene copolymer both copolymers' having been prepared by the process of Hogan et al. and being insoluble in carbon tetrachloride at refluxing temperature or lower.

Two hundred grams of this polymer blend were dissolved in tetrachloroethane at IDS-110 C. and into this solution were passed simultaneously 200 grams of chlorine and 30 grams of sulfur dioxide; the system being maintained at 105-110" C. and under an ultraviolet source. The addition of chlorine and S0 was completed in three hours, after which the reaction mixture was cooled to about 70-80 C. and then 200 cc. of water added. The chlorosulfonated polymer was coagulated by pouring into isopropyl alcohol after which it was separated and washed with additional isopropyl alcohol and then dried at 60 ,6. in a vacuum oven. A yield of 222 grams of product containing 16.1 percent chlorine and 0.59 percent sulfur was obtained.

product was redissolved in 3.3 liters ofcarbon tetrachloride at 60 C. at which temperature the system was maintained during the addition of 100 grams of chlorine and 20 grams of sulfur dioxide for a period of ,3 hours and under ultraviolet light.

The product was recovered as before. The yield was 250 grams with a chlorine c ntent of 26.7 percent and a sulfur content ne of Example 1.

Parts by weight .ChlOrQSHlfonted polymer p 100 Hydr gena ed. resin 5....-- Balcium carbonate Calcined magnesium Dipentamethylenethiuram tetrasulfide 1 in cmio EXAMPLE V Several additional runs were made and physical properties compared with commercial chlorosulfonated poly! ethylene. 1

"Ethylene was polymerized in a continuous process using a reactor provided With a stirrer. Polymerization was effected in the presence of a chromium oxide-silicaalumina catalyst (2.5 weight percent chromium as chromium oxide) using cyclohexane as the solvent. Polymer concentration in the reactor was 8 weight percent, catalyst concentration was 0.5 weight percent, and the residence time was 3 hours. The reaction was effected at a temperature of 280 F. and a pressure of 420 p.s.i.g. Physical properties of the product were as follows:

Molecular weight 1 37,600 Melt Index 2 '137 Volatiles, weight percent 0.02 Ash, weight percent 0.001 .Crystallinity, percent Above 1 Determined by Staudinger equation: Mol. wt.=2.445 inherent viscosltyxlo This is the method of Kemp and Peters, Ind. Eng. Chem., 35, 1108 (1943) and Dienes and Klemm, J. Applied Phys, 17, 458 (June 1946). v 3 Tentative method for measuring flow of thermoplastics by extrusion plastometer, AS'IM D 1238-521.

3 A relative value determined by infrared measurement using a 36- carbon atom hydrocarbon as a standard. 1

The ethylene polymer was chlorosulfonated in three runs. Quantities of materials used in each of the runs were as follows:

A B O Ethylene polymer g 200 200 1 200 Tetrachloroethana. ..l. 3. 5 3. 5v 3. 6 so. 40 .40 40 Cl: 150 200 250 The polymer was dissolved in the tetrachloroethane at 115 C. and the temperatures were maintained at to C. throughout the reaction. Chlorine and sulfur dioxide was introduced simultaneously into the poly mer solution while the mixture was stirred and irradiated *"9 .with ultraviolet light; All of the sulfur dioxide was added with the addition of 100 grams of chlorine. and addition of chlorine was continued until .the desired amount had been introduced. Rate of addition ofchlo- Here again it is shown that these polymers which ar not, susceptible to .chlorosulfonation by the prior art methods can be chlorosulfonated by the method of this invention to give products equal to or better than the rine was approximately 50 grams per hour. After 111 .15 .priorart chlorosnlfonated polyethylene. addition of 200 cc. of water, the product was coagulated by pouring the reaction mixture into isopropyl alcohol. EXAMPLE VI It was filtered Washed wlth isopropylalcpholi An additional run was made wherein a polyethylene o O I A m a Vacuum oven at 60 i for i of high crystalllnlty same as Example H as prepared by The three samples of chlorosulfoaated ethylene. Poly the Hogan et al. method was chlorinated by the prior :rner and two samples of commerc al chlorosulfonated art method as follows Two hundred grams of poly polyethylene l w compounded 99 5 ethylene was added to.3.5 liters of carbontetrachloride wlth h followmg. P x whilethe solvent was refluxing. A slurry was formed'but Fi welght the polyethylene was not in solution. Into the refluxing .chlomsulfonated Polymer --.e-jmixture was passed .40 grams of sulfur dioxide and 200 'HydrQgenated grams of chlorine over a period of three hours while chelplcally PIeCIPItated calcmm carbonate irradiating the flask with ultraviolet light. At the end .cigllcmed 8 of the reaction period, the polyethylene was not solu- Dlpentamethylenethmram tetrasulfide 1 ibilized to any appreciable extent. Data on this run are Thflcompounded Stocks were milled, C -.30 minu shown. as B(L) inthe table. A second run was made as at 307 F., and physical properties determined. Physlcal follows: two hundred grams of polyethylene was added Properties were also determined 011 l.- Slabs Whlch to 3.5 liters of carbon tetrachloride after which'the syse molded from t emncompwnd P Y The stem was heated to refluxing temperature. The poly- .samples were placed in a cold mold, then heated to 250 7 ethylene did not dissolve. An ultraviolet light was pro- -F- Wit out Pressure and held at undef. Pressure .vided and the heat source removed. After cooling to for 35 minutes, and finally cooled to 80? F. under pres- 3 C 100 grams f l i was added Then 1 s r ul Of 3111655 were as follows? I grams of sulfur dioxide and 100 grams of chlorine were added overa period of 3.5 hours. Evaluation data are Chlorosulfonated Commercial Ethylene Polymers I shown 1n the table'as B(2). In a thlrd run two hundred grams of the same polyethylene was'added to 3.5 liters of A B C 1 2 carbontetrachloride after which the slurry was heated at 170 C. for one hour. The ,mixture was thcn'cooled't o Eiiiifiitliiiiiiiiiit11:::::: t? 3715i i? ii i; n ultravidet irradiatipn aPPIied under h 100 grams of chlorlne was added followed by 100 grams V MOLDED RAW P OLYMLRS of chlorine and sulfur dioxide added simultaneously. "I'h:e .finsnemi 1, 35; 85 6Z8 temlperature rose to 60 C. during'the reaction butwas t R 1 3 81102103225521! p n 420 310 200 200 25 oBe(d3 )back to 50 C I The evaluatlon data are shown OOMPOUNDED AND CiIRED 30 MI UTLS AT 7 F p The reaction products: of the above described processes Compression Set, percent 1 22. 4 m2 3 33.6 were recovered by pouring the slurry of chlorosulfonated p elrcent i netiulu si---" 3,2;8 fig n n polymer lnto lsopropyl alcohol, filtering, washing with niti tiieiil ii'556611511111: 300 '520 425 "2 additional isopropyl alcohol and drying in a vacuum oven Residual elongation. percent 105 155 10 5 over i h 200 F. Maximum tensile, p.s.i 980 1,060 1 ,440 1,220 980 i Arena. 50.7 70.6 60.8 Three runs were made utilizing a low density, substani i l ie nge ggt gent Z232 13 2i 2 13 5}; 1 1 52 -ilally lijon-cryzsgallline comlfntelfcially prepared polyethylene. rasionpss, grams n'eac run grams 0 e po yethylene was dissolved -2s -2s -2s 21 -21 3225352825.... a 0 a 0 0 0 0 m llters of carbon tetrachlorlde'at 60-70" C. Chlo- '70/30 123' 6 127.0 92 5 9Z8 line and sulfur dioxide were added simultaneously under -SAEfgI0tGece1iiB1 B 4.4 5.5 3.6 7 2.6 2.4 ultraviolet light at a rate wherein the temperature was 1 ,;,2Z tf 53,9 530 32,5 maintaigied substantially constant. After the chlorine and sul ur dioxide had been added, 200 cc. of water was OVEN AGED 24 HOURS AT 212 added and the mixture stirred 3 to 4 hours. The chloro 300 percent modulus, p.s.isulfonated product was recovered as in the above three g i g sa L3 3 23 3 3 212 3 163 218118, theseS (l)atterdtliree runs dl'cfliered in that in the first AT F! grams 2 an 00 grams 2 were used in the sec- 97 925 91 7,5 83 end 30 grams of S0 and 200 grams C1 were used and Abraslon loss, grams 10.12 15. 44 10.24 12.68 16.20 in the third 5 grams of s and 250 grams of C12 were Same as 1 chemically but of improved processing characteristics and used- The evaluation data are shown 35 C(1), C(21) alil gi s gr eheated 15 minutes at 212F. to soften. and 0(3) the table For comp aratlve purposes data I Relative rating at 14 days: 0=I10 cracks; 10=many large cracks. from previous examples are also given. 4 Two days at 158 F. 6 Fourteen days at 158 F.

B 2 C 8 D 4 A 1 2 3 1 2 a l 2 a Chlorine, percent 27 21. 8 23. 5 24. 2 16. 2 30. 2 34. 5 16. 4 21. 5 28. 8 Sulfur, percent 1.5 0.27 0.53 1.3 5.0 2.8 0. 57 0.69 1.7 1.2 Tensile, p.s.i 125 3, 390 3,240 2,890 800 405 445 2,102 1,950 2,035 Elongation at break,

percent. 2, 8 10 25 835 575 755 738 815 935 1 Commercial chlorostlfonated polyethylene same as Example I.

8 Crystalline polyethylene chlorosulfonated as described above.

8 Commercial polyethylene chloroslilionated as described above. a

Invention product: (1) some as Example III; (2) same as A of Example V; (3) same as C of Example V 11 The products of B appeared to be chlorosulfonated on the surface only and have very low;elongation values.

These data clearly show the advantages of the process of .ride, tetrachloroethane and hexachloroethane at a temperature within the range of 110 to 130 C; and at a pressure sufficient to maintain said solvent in the liquid phase, said ethylene polymer having been prepared by polymerizing monomers comprising at least 50 Weight percent ethylene and the remaining monomeric material being selected from the group consisting of l-olefins and conjugated dienes and having not more than 8 carbon atoms per molecule; introducing sufiicient chlorine to the solution under catalytic conditions to form a chlorinated polymer soluble in halogenated solvents at ambient temperatures; separating said chlorinated polymer from said halogenated solvent; dissolvingsaid separated chlorinated polymer in a halogenatedsolvent selected fromsaidaforementioned group at a temperature in the range of ,25 to 60 C., said halogenated solvent being different from the first selected halogenated solvent; introducing additional chlorine and sulfur dioxide to the resulting solution under catalytic conditions until the polymer has a chlorine content within the range of 10 to 40 weight percent and a sulfur content within the range of 0.3 to 4 weight percent; and thereafter recovering the chlorosulfonated polymer from solution.

2. The process of claim .1 wherein the polymer is polyethylene.

3. The process of claim -1 wherein the polymer is a copolymer of ethylene and a comonomer of up to 8 carbon atoms selected from the group consisting of 1-olefins and conjugated dienes.

4. The process of claim .3 wherein the comonomer is propylene.

5. A process for producing a novel chlorosulfqnated polymer which comprises dissolving an ethylene polymer, which is insoluble in carbon tetrachloride at atmospheric pressure and at refluxing temperature, in a halogenated solvent selected from the group consisting of carbon tetrachloride, chloroform, trichloroethane, methylene chloride,

tetrachloroethane and hexachloroethane .at a tempera 1 2 'ture within the range of to C. and at a pressure sufficient to maintain said solvent in the liquid phase, said ethylene polymer having been prepared by -polymerizing monomers comprising at least 50 weight percent ethylene and the remaining monomeric material being selected from the group consisting of l-olefins and conjugated dienes and having not more than 8 carbon atoms per molecule; introducing sufi'icient chlorineto the solution under catalytic conditions to form a chlorinated polymer soluble in halogenated solvents at ambient temperatures; separating said chlorinated polymer from said halogenated solvent; dissolving said separated chlorinated polymer in a halogenated solvent selected from said afore mentioned group at a temperature .in the range of 25 to 60 'C., said halogenated solvent being different from the vfirst selected halogenated solvent; introducing additional chlorine and sulfur dioxide to the resulting solution under catalytic conditions until the polymer has a chlorine con.-

,to .this solution under catalytic conditions to forrna chlorinated polyethylene soluble in carbon tetrachloride at ambient temperatures; coagulating said chlorinated polyethylene in solution in said tetrachloroethane; sepa rating said coagulated chlorinated polyethylene from said tetrachloroethane; dissolving said separated chlorinated polyethylene in carbon tetrachloride at a temperature in the range of 25 to 60 0.; introducing additional chlorine and sulfur dioxide to the resulting solution under catalytic conditions until the polymer has a chlorine content within the range of 10 to 40 weight percent and Ya sulfur content within the range of 0.3 to 4 weight percent; and thereafter recovering the .chlorosulfonated polymer from solution.

References Cited in the file of this patent UNITED STATES PATENTS 2,212,786 McQueen Aug. 27, [1940 2,721,189 Anderson et a1. r Oct. 18, 1955 2,726,231 Field et al. v Dec. 6, 1955 2,762,791 Pease et a1 Sept. 11, 1956 2,879,261 Johnson et a1. Mar. 24, -9 

1. A PROCESS FOR PRODUCING A NOVEL CHLOROSULFONATED POLYMER WHICH COMPRISES DISSOLVING AN ETHYLENE POLYMER HAVING A CRYSTALLINITY OF AT LEAST 80 PERCENT AT ROOM TEMPERATURE AND A DENSITY OF AT LEAST 0.96 IN A HALOGENATED SOLVENT SELECTED FROM THE GROUP CONSISTING OF CARBON TETRACHLORIDE, CHLOROFORM, TRICHLOROETHANE, METHYLENE CHLORIDE, TETRACHLOROETHANE AND HEXACHLOROETHANE AT A TEMPERATURE WITHIN THE RANGE OF 110 TO 130*C. AND AT A PRESSURE SUFFICIENT TO MAINTAIN SAID SOLVENT IN THE LIQUID PHASE, SAID ETHYLENE POLYMER HAVING BEEN PREPARED BY POLYMERIXING MONOMERS COMPRISING AT LEAST 50 WEIGHT PERCENT ETHYLENE AND THE REMAINING MONOMERIC MATERIAL BEING SELECTED FROM THE GROUP CONSISTING OF 1-OLEFINS AND CONJUGATED DIENES AND HAVING NOT MORE THAN 8 CARBON ATOMS PER MOLECULE, INTRODUCING SUFFICIENT CHLORINE TO THE SOLUTION UNDER CATALYTIC CONDITIONS TO FORM A CHLORINATED POLYMER SOLUBLE IN HALOGENATED SOLVENTS AT AMBIENT TEMPERATURES, SEPARATING SAID CHLORINATED POLYMER FROM SAID HALOGENATED SOLVENT, DISSOLVING SAID SEPARATED CHLORINATED POLYMER IN A HALOGENATED SOLVENT SELECTED FROM SAID AFOREMENTIONED GROUP AT A TEMPERATURE IN THE RANGE OF 25 TO 60*C., SAID HALOGENATED SOLVENT BEING DIFFERENT FROM THE FIRST SELECTED HALOGENATED SOLVENT, INTRODUCING ADDITIONAL CHLORINE AND SULFUR DIOXIDE TO THE RESULTING SOLUTION UNDER CATALYTIC CONDITIONS UNTIL THE POLYMER HAS A CHLORINE CONTENT WITHIN THE RANGE OF 10 TO 40 WEIGHT PERCENT AND A SULFUR CONTENT WITHIN THE RANGE OF 0.3 TO 4 WEIGHT PERCENT, AND THEREAFTER RECEIVING THE CHLOROSULFONATED POLYMER FROM SOLUTION. 